I. Field of the Invention
This invention relates to a thread brake for a two-for-one textile spindle.
II. Description of the Prior Art
A thread brake of this general nature is described in DE-OS 20 50 490 and may be the sole braking system for a thread in the range of a processing station or such a thread brake may be associated with a further braking point as a preceding or subsequent brake in the thread line.
In the threading-in or threading-through of a yarn or thread, particularly in the pneumatic threading, it is either necessary to provide for an unobstructed passage for the thread, namely, by lifting the brake element off the brake surface ring, or to provide for a by-pass passage extending parallel to the actual braking point which is formed by the brake surface ring and the brake element as described, e.g., in DE-PS 30 15 182, corresponding to U.S. Pat. No. 4,405,094. In such a pneumatically threadable brake, the thread may be pneumatically passed laterally of the actual braking point so that, upon tensioning of the thread during the start-up of the processing station, the thread is drawn through a lateral slot in the brake surface ring, into the annular opening thereof. In the thread brake as described in DE-PS 30 15 182, the annular opening of the brake surface ring is radially offset with respect to the thread inlet openings so that, during ordinary travel of the thread through the thread brake, varying thread tensions will occur during the movement of the thread around the brake element or the axis of the brake housing, respectively.